on another forum I saw a thread where a member restored his 30+ year old red dirt bike plastic from faded white to nice red using a razor ( or sandpaper) and heat. I have not tried this but if someone sends me their red fender wells I will give it a go.

i would guess this would work well on black fender wells or other similar plastic

heres a couple representative pics there are more pics on the original thread

https://thumpertalk.com/forums/topic...r-restoration/